Fisher's Exact Test for contingency tables with more than 2 rows
and/or more
than 2 columns
To run Fisher's exact test under Windows, you need three files:
fisher.exe,
grid.vbx and vbrun300.dll.
1. Download fisher.ex by clicking its name and
put it in any folder of your choice.
2. Then change its name to fisher.exe (files with .exe suffixes may be
barred by communications software in the interests of security, hence
the need to change its name).
3. If you don't already have them, download grid.vbx
and vbrun300.dll by clicking their names
with
the right-hand mouse button and selecting "Save link as" or "Save
target as". Put them in your windows system folder, i.e. in
c:\windows\system
or c:\winnt\system.
You can then run the program by double-clicking Fisher.exe with Windows
explorer, or by creating a shortcut to it. There is no need to run any
installation software.
Limitations of the Program
As far as I know, this is the only freely available program that will
analyse
a contingency table of more than rows and 2 columns by Fisher's exact
test.
The number of rows and columns it will cope with are dictated not by
any
limitations imposed by the software, but by the limitations of your
processor
speed.
Using a 1.8 MHz Pentium 4, the following contingency table can be
analysed
in about 1 second, but the time taken increases immensely with larger
tables.
3 1 0 6
1 4 4 2
0 1 5 0
Description of how the program works
The statistical theory of the method and an outline of the algorithms
used
is given here as a Word document. To read the formulae in it properly
you need to install the Equation Editor that comes with Word. Download
document
Source code
As an aid to checking the logic of the computation, the main parts of
the
source code are provided here.
Download source code